The whole thing boils down to property taxes, obviously. Americans don't think beyond their own districts, typically - something deep needs to change, there, for any real progress to ever happen. Additionally, California at least is still staggering under the effects of Proposition 13. Liberals aren't totally averse to tax-slashing schemes with lots of unintended consequences like that.

I'm sure there are piles of other causes I can't even guess at, too.